Insecticide



Patented June 25, 1946 STATES PATENT ()FFICE INSECTICIDE Theodore W. Kerr, Jr., Seymour, Conn, assignor to United States Rubber Company, New York, N. Y., a corporation of New Jersey N Drawing. Application November 15, 1944,

Serial No. 563,621

2 Claims.

solved powder dispersed in water, If desired, the

insecticides may be applied in a mutual solvent medium.

The following examples, which are illustrative of the invention, clearly show the synergistic insecticidal effect of mixtures of 2,2-bis(p-chlorophenyl) -1,1,1-tri chloroethane and the oily product of the condensation of monochlorobenzene and ethylene chloride. The 2,2-bis(p-chlorophenyl) -1,1,1-trichloroethane used was prepared in the conventional manner by reacting 1' mol mula 2,2-bis(aromatic radical)-1,l,1-trihaloethone that may be used are 2,2-bis(phenyl)-1,1,1- trichloroethane, 2,2 bis (p chlorophenyl) -l-,1,1- trichloroethane, 2,2-bis( naphthyl) -1,1,1' trichloroethane, 2,2-bis(p xenyl) -1,l,1 trichloroethane, 2,2 bis(p thiocyanophenyl) -1,1,1 trichloroethane, 2,2-bis(p-tolyl)-1,1,1-trichloroeth ane. These may-be prepared in known manner by condensing chloral or chloral hydrate with the desired aromatic compound to give theselected aromatic radical in the general formula. Examples of aromatic hydrocarbons and nuclearhalogen substitution products thereof that may be condensed with alkylene halides as shown in the ter Horst Patent No. 2,243,543 are benzene, monochlorobenzene, dichlorobenzene, trichlorobenzene, benzylchloride, diphenyls, chlorinated diphenyls, dibenzyl, toluene, xylene, ethylbenzene, naphthalene. are methylene chloride, ethylene chloride, propylene chloride, amylene chloride, tetrachlorethane, trichlorethylene.

The compounds having the general formula 2,2bis(aromatic radical) -1,l,1-trihaloethane are solids and are soluble to a relatively high concentration in the oily condensation products of the aromatic hydrocarbons or the nuclear-halogen substitution products thereof with alkylene halides. For example, 2,2-b is(p-chlorophenyl)- 1,1,1-trichloroethane is soluble in the oily condensation product. of monochlorobenzene and ethylene chloride to the extent of over 30 parts of the former per 100 parts of the latter. It is preferred to use such solutions emulsified in water with the aid of commercial wetting agents as insecticides, but if desired the two materials may be separately dispersed and mixed together, or an excess of the solid powder over the amount that is soluble in the oily condensation product Examples of the alkylene halides of chloral with 2 mols of monochlorobenzene in the presence of an excess of concentrated sulfuric acid. After the reaction had stopped, the

mixture was poured into a large amount of water, whereupon the 2,2-bis(p-chlorophenyl)- 1,1,1-trichloroethane separated out. It-may be washed and recrystallized from alcohol. The oily product of the condensation of monochlorobenzene with ethylene chloride was prepared similarly to Example 3 of the ter Horst Patent No. 2,243,543 by reacting equimolar proportions of monochlorobenzene and ethylene chloride in the presence of aluminum chloride'for sixhours, stopping the reaction by the addition of water, and separating the oily lower layertfl Unreacted monochlorobenzene and ethylene chloride were whole oil. The fraction of this whole oil dis tilling at Mil-165 C. at 3 mm. mercury pressure was also used in some of the examples, and will be termed fraction oil. The examples below describe tests showing the action on various insects of aqueous dispersions of the 2,2-bis(pchlorophenyl)-1,1,1-trichloroethane, whole oil,

fraction oil, and mixtures of the same which were prepared at the desired dilutions for the various tests in the conventional manner, with the aid of suitable dispersing and wetting agents in amounts which were known to be non-toxic to the insects under test.

Example I The eifectiveness of the 2,2-bis(p-chlorophenyl) -1,1,1-trichloroethane, the whole oil, the fraction oil, and mixtures of the 2,2-bis(pchlorophenyl)-1,1,1-trichloroethane with the whole oil, and with the fraction oil, was

tested against the potato aphid, Macrosiphum solanifoliz', by spraying potato leaves infested with may be used and the solution with the undisthe aphids with aqueous dispersions of the in- The percentage mortality on the potato aphids after 24 hours of 1-200 dilutions of the insecticides was 8.0% for the 2,2-bis(p-chlorophenyl)- 1,1,1-trichloroethane, 11.4% for the "whole oil,"-

and 24.3% for the "fraction 011. 1-20() dilutions ofa mixture of 1 part of 2,2-bis(p-chlorophenyl)-1,l,l trichloroethane .to 3 parts of the "whole oil, and to 3 parts of the "fraction oil," gave 64.9% mortality for the mixture of the 2,2- bisip-chlorophenyl)-1,1,1-trichloroethane with the "whole oil," and 70.9% mortality for the mixture of the 2,2,-bis(p-chlorophenyl)-1,1,1-trichloroethane with the fraction oil," showing very definite synergistic action of the mixtures of the known insecticides.

A 1-800 dilution of 2,2-bis(p-chlorophenyl)- 1,1,1-trichloroethane sprayed on potato aphids showed 15.4% mortality of the aphids alter 24 hours. A 1-266 dilution of the whole oil showed 11.7% mortality after 24 hours. An aqueous dispersion of a mixture containing 1-800 dilution of 2,2-bis(p-chlorophenyl) -1,l,1-trichlomethane and 1-266' dilution of the "whole 011" showed 65.5% mortality after 24 hours, again illustrating the synergistic action of the mixture of known insecticides.

' Example II The synergistic eilects found in the above tests were corroborated in field trials. Four rephcates, each containing two, twenty-five foot rows of potato plants, were used for each treatment, and also for the control (untreated). lutions of 2,2-bis(p-chlorophenyl)-l,1,1-trichloroethane, of fraction oil, and of a mixture of 1 part 2,2 bis(p-chlorophenyl) 1,1,1 trichloroethane to 3 parts --fra.ction oil respectively, were sprayed on rows of potato plants as described above. Forty-eight hours after treatment potato insect populations were sampled by making ten sweeps with a twelve inch net in each replicate of each treatment and of the control. The average number of potato aphids per sweep of the net was .95 for the control, 1.05 for the 2,2- bis (p chlorophenyl) 1,1,1 trichloroethane, .60 for the fraction oil,','and .25 for the mixture of 2,2-bis(p-chlorophenyl) 1,1,1 trichloroethane with the fraction oil.

* Example III 2,2 bis(p-chlorophenyl) f;1.,1 trichloroeth- 4 test. The percentage mortality was determined after 24 hours. A 1-800 dilution of 2,2-bis (pchlorophenyl)-1,1,1-trichloroethane gave 27.0% mortality. A 1466 dilution of whole oil gave 47.6% mortality. An aqueous dispersion of a mixture containing l800 dilution of 2,2-bis(pchlorophenyl) 1,1,1 trichloroethane and 1-286 dilution of the whole oil gave 85.2% mortality.

2,2 bis(p-chlorophenyl) 1,1,1 trichloroethane, and "traction oil. and a mixture oi. the two, were similarly tested against pea aphids by spraying broad bean leaves infested with the aphids with 1-200 dilutions of the insecticide un der test. There were a7 to 104 insects in four replicates of each test. The percentage mortality on the pea aphids after 24 hours of 1-200 dilutions of the insecticides was 50.6% for the 2,2-bis(pchiorophenyl) 1,1,1 trichioroethane, and 64.8% for the fraction oil." A l200 dilution of a mixture 01' 2.5 parts of 2,2-bis(p-chlorophenyl)-1,1,1-trichloroethane to 7.5 parts 01' the fraction oil" gave 92.3% mortality.

Example IV 2,2 bis(p-chlorophenyl) 1,1,1 trlehloroethane, and whole oil" and a mixture of the two, were tested against the Mexican bean beetle (Epilachna vari'uestis), by spraying bean leaves which were later infested by beetles with aqueous dispersions of the chemicals to be tested. There were 40 beetles in the four replicated tests with each dispersion. A 1-1089 dilution of 2,2-bis(pchlorophenyl)-1,l,1-trichloroethane gave 5% mortality. A 1-363 dilution of whole oil gave 37.5% mortality. A dispersion of a mixture containing l-800 dilution of 2.2-bis(p-chlorophenyl)-l,l,l-trichloroethane and 1-363 dilution of "whole oil" gave 92.5% mortality.

The synergisticfinsecticidal action of compositions containing 2,2-bis(p-chlorophenyl)-1,1,1-

trichloroethane and the oily product of the con- THEODORE w. KERR, Ja. 

